Collection of used cooking grease is a competitive field. Restaurants that use cooking grease typically contract with a vendor, who provides a grease storage tank at the restaurant and collects used grease from the storage tank at scheduled intervals. The used grease is then processed at a central facility and converted into soap, plasticizers, and other products.
Restaurants use a large quantity of grease every day. At some point, the grease becomes undesirable for further use, and must be disposed of. The grease, in a liquid form and generally still heated above the ambient temperature, is poured into a storage vessel for later retrieval by a collector. Previously, used grease was stored in barrels, which resulted in large amounts of spillage and necessitated frequent collection of the grease or use of multiple barrels for storage. An improvement was made whereby large, centrally located storage tanks replaced the smaller, individual barrels. Cooking grease from various locations in the restaurant is transported to a central grease storage tank, which is typically located outside the restaurant, usually in an alley or location with vehicular access for the collector.
Grease storage tanks are generally large containers, often shaped like a dumpster, or possibly a horizontally oriented cylindrical tank, with a centrally located lid that opens up to receive the grease. Under the lid is a grease inlet port. Generally, the grease inlet port is located high off the ground, creating a dangerous condition in which restaurant personnel must lift the hot liquid grease high into the air in order to pour the grease into the tank, thereby exposing themselves to risk of injury and increasing the chances of spillage. In addition, access to the lid, and thus the tank, is generally available only from one side of the tank.
Grease storage tanks are generally constructed of steel and are susceptible to rust from standing water and moisture accumulation due to poor water runoff. Corrosion from moisture buildup on the top outside and bottom outer surface of grease tanks significantly shortens the working life of the tanks.
Lids or covers for grease tanks are also generally constructed of steel, making them heavy and burdensome for restaurant personnel to open and, once open, difficult to close.
Used cooking grease is a valuable commodity, and a large tank of grease is an attractive target for thieves. Tanks that provide large lids and relatively easy access for restaurant personnel also provide easy access for thieves looking to steal large quantities of grease in a single stop. To prevent theft, some tanks are designed with smaller grease inlet ports, which make it more difficult for restaurant personnel to pour the hot cooking grease into the storage tank without spilling the grease and/or burning themselves. Smaller grease inlet ports not only make a difficult target for pouring the hot liquid, but also require that the used cooking grease be poured sufficiently slowly to avoid overflowing the grease receiving area, again increasing the chance of injury or spillage.
One anti-theft measure that has been used is the provision of a padlock for the lid or cover. However, the lock is generally exposed and subject to destruction from the outside. In addition, the lock can be circumvented by a grease thief armed with a bolt cutter.
Thus, there exists a need for a grease tank providing ease of use, safety, security, durability, and weatherability.